⚡️(ci) cache Playwright browsers by version

Key the Playwright browser cache by the installed @playwright/test
version instead of yarn.lock so cache hits actually match the binaries
Playwright expects, avoiding redundant browser downloads on every CI
run. On cache hit we still install system deps to keep headless runs
working.

.github/workflows/drive-frontend.yml

@@ -98,17 +98,30 @@ jobs:
           path: "src/backend/core/templates/mail"
           key: mail-templates-${{ hashFiles('src/mail/mjml') }}
 
+      - name: Get Playwright version
+        id: playwright-version
+        run: |
+          VERSION=$(node -p "require('./src/frontend/apps/e2e/package.json').devDependencies['@playwright/test'] || require('./src/frontend/apps/e2e/package.json').dependencies['@playwright/test']")
+          echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
+
       - name: Cache Playwright browsers
         id: playwright-cache
         uses: actions/cache@v4
         with:
           path: ~/.cache/ms-playwright
-          key: playwright-${{ matrix.browser }}-${{ hashFiles('src/frontend/**/yarn.lock') }}
+          key: playwright-${{ runner.os }}-${{ matrix.browser }}-${{ steps.playwright-version.outputs.version }}
 
-      - name: Install Playwright Browsers
+      - name: Install Playwright Browsers (cache miss)
+        if: steps.playwright-cache.outputs.cache-hit != 'true'
         run: |
           cd src/frontend/apps/e2e
-          npx playwright install --with-deps ${{matrix.browser}}
+          npx playwright install --with-deps ${{ matrix.browser }}
+
+      - name: Install Playwright system deps (cache hit)
+        if: steps.playwright-cache.outputs.cache-hit == 'true'
+        run: |
+          cd src/frontend/apps/e2e
+          npx playwright install-deps ${{ matrix.browser }}
 
       - name: Start Docker services
         run: |